Question

(0,09) −1⁄2 + (−27) 0,333…

Answer 1

Explicação passo-a-passo:

Correct option is

D

9

We know that sum of n terms of an A.P. is given by

Sk=2k{2a1+(k−1)d}

So,SnSm=SnS5n=2n{6+(n−1)d}25n{6+(5n−1)d}=n{6+(n−1)d}5n{6+(5n−1)d}={(6−d)+n}5{(6−d)+5nd}

Since, SnSm is independent of n , so d=6.

If d=6 then a2=a1+d=3+6=9